Questions tagged [electron]

Anything related to the behavior and properties of electrons, i.e. the elementary subatomic particles accounting for electrical conduction in most solid materials, especially metals.

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Deflection of current in a metal plate conductor

If I have a metal plate (square in shape) and an electric current moves from one side to the other. I understand that most of the current will take the path of least resistance but all paths will be ...
Daniel's user avatar
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How to calculate the diffusion length in modulation doping?

I have read a paper about an application of modulation doping in bulk thermoelectric materials. In this paper, the nanoparticles diffuse carriers into the host materials, and I want to estimate the ...
orz's user avatar
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4 answers
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Why do electrons move in a circuit? [closed]

I am trying to make sense of why electrons move in a circuit. I did my research and the first answer I got is because of the difference of electric potential between the two points of the battery that ...
majduddin's user avatar
1 vote
1 answer
95 views

Current in BJT at EBJ and its mechanism about Diffusion and Drift Current

I have seen this post and I'm still confused about what mechanism would be applied on majority carrier, and it seems to me that the post I cite only explain about how the minority carrier move from ...
Ting-Kai Hsu's user avatar
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2 answers
63 views

How I can use light to control of amplifier?

I want to make a car that I can control by light, and I thought of using a photoresistor and a light sensor to control the amplifier to make it perform two functions. The first function is to make the ...
Mohammed Al-Elaiwi's user avatar
3 votes
3 answers
1k views

Is it possible to make cathode ray or electron gun without a vacuum?

I stumbled upon this picture on the internet here is the link https://www.reddit.com/r/ElectroBOOM/comments/16azeq5/cathode_ray_succesfully_shooting_a_plasma_beam_in/ I wasn't able to get info from ...
Majd's user avatar
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1 answer
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Propagation speed and capacitors charging speed of transmission line

I am a bit confused on the speed of voltage propagation in the transmission line and I hope someone can enlighten me. I understand the speed of step up voltage propagation is in the same order as the ...
eyew18's user avatar
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5 answers
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Why does the neon screwdriver (phase meter) light on just by touching the phase wire?

I had a question, can you answer it: as you can see in the picture I uploaded, the single-phase alternating current flows in one wire at one moment and in the next moment from another wire as in the ...
Mahdi's user avatar
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2 answers
78 views

Two power sources

Please consider a circuit with two loops where the two loops have a common part with a single resistor. There are two power supplies (or of it matters say these are voltage sources, like batteries, ...
ssheep's user avatar
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2 answers
110 views

Is there a colour code for electron flow notation? [closed]

I'm building a power supply for electro-chemistry experiments. It would make more sense to have the output correctly denote which terminal is 'electro-negative' and which is 'electro-positive' instead ...
Slartibartfast's user avatar
1 vote
3 answers
146 views

Moving electrons on the surface of a thin metal sheet with high current

I don't know if this is the right place to ask this because my question is a mix of physics and electronics. I'm in 12 grade, and wish to conduct a simple physics experiment. I would like to observe ...
44yu5h's user avatar
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Trying to understand electron flow in a rapid start ballast fluorescent light system

While looking into what is required to upgrade a fluorescent tube light to a LED solution, I found that I don't truly understand what is happening with existing fluorescent solutions. I understand the ...
RJ White's user avatar
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1 answer
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Effective Mass of Electrons

In electronics, the fact that mobility of electrons is higher than the mobility of holes is frequently used. How can we explain this using effective mass of electrons and holes ?
Arinjoy Pramanik's user avatar
1 vote
1 answer
226 views

What is the total charge Q of 1 m³ of copper?

I was wondering if I can calculate the total charge Q of 1 m3 of copper, see my calculation in the picture below. Is this correct? The correct solution (thanks to the community in the comments below):...
Marco Moldenhauer's user avatar
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1 answer
42 views

Reasoning behind the density of free electrons/holes being constant with respect to volume of a semiconductor material

Consider a silicon semiconductor material which is having a cuboid shape of dimensions \$2\times 2\times 1\ \mathrm{cc}\$, suppose the atomic density of silicon is \$10^{22}/\mathrm{cc}\$, so in all ...
ProblemDestroyer's user avatar
3 votes
2 answers
303 views

How do receiver circuits differentiate between carrier/signal waves?

I've been told and shown that a receiving antenna will pretty much pick up any signals around itself. You can then filter out the frequency you want in order to do something with it. What I don't ...
Andrey's user avatar
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2 answers
838 views

Can electron microscopes record video of electricity?

Since electron microscopes capture electrons, can they be used to capture electrons moving in a circuit, and have they been used for this?
Dashiell Rose Bark-Huss's user avatar
-1 votes
2 answers
109 views

Conventional current and electron flow in Arduino

On an Arduino there are some pins named GND, some are 5 V, and so on. If electrons flow from the negative to the positive terminal, then does this mean that they are flowing from GND to one of the ...
TrojanMouse's user avatar
3 votes
2 answers
132 views

Fermi level of metal

Do metals have fermi level? As we know conduction band and valence band are overlaped for a metal. Does it make any sense for metals to have fermi level?
sumita sahu's user avatar
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2 answers
152 views

Can very small currents be accurately measured using only standard analog electronic components on an IC? [closed]

Let's say, for example, that I have a photodiode, which produces electrons in response to the amount of light. What is the theoretical lower limit that can be accurately measured only using basic ...
Ching Chung's user avatar
2 votes
0 answers
102 views

Is it possible to force charges into one plate of a capacitor?

As we know, a capacitor stores energy, but the net amount of charge in it doesn't change. If an electron enters one plate, another leaves the other plate. If the other plate is floating, the entering ...
Bart van Heukelom's user avatar
16 votes
4 answers
2k views

Why don't most electrons hit the anode in a cathode ray tube or electron gun?

In a cathode ray tube or electron gun, electrons liberated from the cathode by thermal emission accelerate towards a ring-shaped anode, from the potential difference between cathode and anode. If an ...
sqek's user avatar
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2 votes
5 answers
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Do electrons flow from higher to lower or lower to higher potential?

I have seen countless sites saying electrons flow from higher potential to lower potential, but then again I have seen many saying that electrons flow from lower potential to higher. I have always ...
PaAnda's user avatar
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-1 votes
2 answers
152 views

Are vehicle electrical components powered from the negative side?

still trying to get my head around electron flow as opposed to conventional current regarding automotive electrical circuits. There seems to be a ton of conflicting information/advice out there so I'm ...
TMax's user avatar
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2 votes
4 answers
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How is current the derivative of charge

If electric current is the time rate of CHANGE of charge. Then if I have a DC fixed current flowing into a resistor, same amount of charge is always flowing to that resistor, hence the derivative of ...
alayoiskgfbfqhxjiw's user avatar
-1 votes
2 answers
3k views

The probability that an electron occupies the fermi level at 0K

I was trying to find the probability that an electron occupies the Fermi level at 0K. Fermi function: {exp[(E-Ef)/kT] + 1}-1; (k = 8.314 J/mol/K) According to my calculations, the answer would be 0.5. ...
Kavindu Nilshan's user avatar
-1 votes
1 answer
186 views

3 Phase Motor to DC Output

In a standard car alternator there is are 3 diodes that keep each of the phases from ever pulling electrons. There is then a capacitor to smoothens it all out. However how is it possible that the ...
Moshe Dicker's user avatar
0 votes
2 answers
88 views

KCL when rate of electron flow is given ; To include electron sign or not

Q) We have to determine the I. Magnitude of electron charge is 1.6 x 10^-19C. I have fundamental confusion in this problem. Should we consider the negative charge of electron while doing the problem. ...
TapasX's user avatar
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0 answers
60 views

Generation of electrostatic induction

I need to generate a 500 volt electrostatic charge. How can I do this? I don't have a Van de Graaff generator. What are some practical suggestions? Basically I want to do an experiment in which I need ...
Aniket Kumar's user avatar
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0 answers
28 views

Repelling charges and current flow

The electrostatic force between two like charges is repelling. This concept is fairly clear to me with Coulomb's law and electric fields. So two electrons will repel each other. Given this statement, ...
Rabih Sarieddine's user avatar
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1 answer
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Why are low band gap semiconductors (like silicon) not ideal for most solar cells? Are their atoms ionized by higher-energy photons?

Most sources on the web say that 1.3 eV or 1.4 eV is 'ideal' for most solar cells... What happens to lower-gap, gapless or overlap materials (conductors)? Are they ionized, rather than sending their ...
Kurt Hikes's user avatar
0 votes
3 answers
1k views

Why is there EMF present when there is no current?

Current means the rate of flow of charge. Electrons are the ones that carry charge in current. From the definition of EMF (electromotive force), When no current is drawn from cell, the potential ...
S.M.T's user avatar
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-1 votes
5 answers
625 views

What does charge on an electron mean?

As I have read , charge is electrons , protons or neutrons. Now , according to definition of current , current is the rate of flow of charge I.e flow of electrons. Then , I=Q/t . Unit of Q is coulomb &...
S.M.T's user avatar
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1 vote
1 answer
107 views

Majority Charge carriers and electron holes

Suppose I have an extrinsic semiconductor made of silicon and doped with phosphorous. Now, phosphorous has one more electron than silicon. After replacing one silicon atom, and taking its place, the ...
Nakshatra Gangopadhay's user avatar
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0 answers
240 views

Shelly 1 Configuration

I am trying to implement the Shelly 1 switch for an electronic device I have. The electronic device has an open collector output channel (AUX1). It also has two output pins Z8 and C. When Z8 and C are ...
solutery7's user avatar
0 votes
2 answers
94 views

Can current flow from positive to positive in real life

How to implement a circuit diagram where there are 2 batteries and negative to negative have load and postive to positive have some load. How to implement, like build in real life this ...
Aamirshah SHAIK's user avatar
4 votes
8 answers
3k views

Is there a mnemonic to remember direction of current flow?

I have always stumbled when remembering which current flow notation to use. In my mind, it's by default conventional current flow. But, I also have in mind electron flow notation. Do you know of a ...
Nick Bolton's user avatar
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0 votes
2 answers
574 views

How many newtons are there in one coulomb of charge?

Or, I should have said, how many newtons of force does one coulomb of charge exert? At a distance, presumably, of one meter? Since N/C is supposedly equivalent to V/m? P.S. What are the values for a ...
Kurt Hikes's user avatar
0 votes
1 answer
92 views

Removing collected charges in a IC CMOS circuit exposed under a 30keV electron beam source

I would like to know if there is any mechanism (for example UV light exposition) to remove charges collected in an IC CMOS circuit that was exposed under a 30keV electron beam source. Presumably, ...
Jorge Johanny Sáenz Noval's user avatar
7 votes
1 answer
646 views

Can a floating capacitor terminal be used to collect electrons?

I want to collect charge from an electron beam source. For that, I'm proposing to put a floating capacitor with its bottom terminal floating and directly exposed to the electron beam gun. The top ...
Jorge Johanny Sáenz Noval's user avatar
1 vote
4 answers
178 views

Why does current continue flowing in a circuit?

Sorry for the amateur question, but I'm having trouble understanding this phenomenon. In a closed circuit, electron current flows from the negative terminal of a battery to the positive terminal. But ...
Lily Morgan's user avatar
0 votes
4 answers
116 views

Signal interference in receiving antenna?

I’ve been scouring the interweebs for some insight into how electrical signals travel in a wire. More specifically, I cannot wrap my head around how a receiving antenna works with hundreds if not ...
Chrispiddy's user avatar
23 votes
8 answers
6k views

In which direction do electric signals flow?

We know that electrons move from the negative to positive terminal, and that holes flow in the conventional direction of current - from the positive to negative terminal. I've always assumed that this ...
slebetman's user avatar
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1 vote
2 answers
840 views

Electrons flow in Li-ion Battery

I’m new to electricity, and I’ve got a question about electrons flow inside a Li-on battery. A lot of articles and videos show us only Li+ ion flows from anode to cathode through electrolyte during ...
Vasilly Fedorov's user avatar
0 votes
1 answer
86 views

How do I make a “directed” spark gap?

(Originally asked on engineering StackExchange, I was directed to ask it here) For a project, I need to create a spark gap that only triggers when there is a conducting material between the 2 contacts....
Mat NX's user avatar
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1 vote
1 answer
1k views

How does a single phase shared neutral circuit actually work, physically?

Okay so this is a two part question. First Question is probably more of an ELI5 question. But I am a fairly experienced electrician (NOT AN ENGINEER mind you.) but I have a generally good working ...
ElectricianPat's user avatar
4 votes
2 answers
440 views

How can electrons in a tungsten filament release infrared light photons?

I have a question regarding electric circuits, specifically when it comes to converting electromagnetic energy into light in a light bulb (tungsten)filament. How can an electron in a tungsten atom of ...
user211797's user avatar
1 vote
0 answers
283 views

Mobility of electrons vs holes in semiconductors (intrinsic vs extrinsic)

I was reading my class notes and it was written that electrons are more mobile than holes because the effective mass of electrons are lower than that of holes. (μ=eτ/m*) I checked online to find the ...
Gourab's user avatar
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2 votes
0 answers
204 views

What does the fermi-level increase in reverse-bias?

Fermi-level tells us the probability of finding an electron at 50%. When you look at an energy band diagram in reverse-bias you can see the Fermi-level increases in the p-type semi-conductor. Why does ...
Faheem Azeemi's user avatar
2 votes
0 answers
65 views

In an energy band diagram why is the valance band in the p-type have more energy then n-type?

I am having trouble understanding energy band diagrams. In an energy band diagram of a semi-conductor during equilibrium the valence band of the p-type is higher then n-type meaning electrons in the ...
Faheem 's user avatar